Polyvinyl chloride solution and method of making the same



March 11, 1941. 2,234,212

POLYVINYL CHLORIDE SOLUTION AND METHOD OF MAKING THE SAME R. F. WOLF Filed. March 2, i939 Fl/PFUFAL 'c/rzwwfA/zfzvz J?? L/E'ZZ7Z7E *5? i2 43 k q 70 \l' I Patented Mar. 11, 19 1 I 2,234,212 1 UNITED STATES PATENT OFFICE POLYVINYL CHLORIDE SOLUTION AND METHOD OF MAKING THE SAME Ralph F. Wolf, Cuyahoga Falls, Ohio, assignor to The B. F. Goodrich Company, New York, N. Y, a corporation of New York Application March 2, 1939, Serial No. 259,340

4 Clalms. (CL 260--32) This invention relates to solutions of polyparts by weight of gamma polyvinyl chloride in vinyl chlorides, and to a method of making the 90 parts by weight of solvent by heating the same. i 7 components in a beaker in an oil bath. The so- It is well knownthat the solubility of polylution was cooled with constant stirring until vinyl chloride prepared by different methods it gelled and would no longer flow from the bulb g varies considerably. This invention is concerned oi the thermometer. with the insoluble or. gamma polymer of vinyl It can be seen in Fig. 1 that the gel points chloride. While hydrocarbon solvents in genof solutions in which the chlortoluene contains eral do not dissolve gamma polyvinyl chloride 30-100% of tetrahydrofuriuryl alcohol are low- 10 at any temperature it is known that chlorinated ered even below the gel point of a solution 01 the l benzene and its homologues are solvents for gamma polymer in. tetrahydrofurmryl alcohol gamma polyvinyl chloride at elevated temperaalone. It was ioimd that from 20l00% oi tet- -tures. It has been found, however, that the gel rahydroiuriuryl alcohol could be mixed with point of such solutions is rather high which chlorbenzene, which alone gave a 10% solution renders it impossible to deposit from solution having a gel point oi! 73, to produce solutions 1 films of gamma polyvinyl chloride either in a having gel points below 68 C. plasticized or an unplasticized iorm except at As can be seen from Fig. 2, iuriural, which high temperatures. Thus the gel point of a 10% alone gave a 10% solution having a gel point of solution of gamma polyvinyl chloride in chlor- 72, could be mixed with chlortoluene in proporbenzene is 73 C., in chlortoluen is 84' 0., and tions of from about ill-100% to give solutions 1 in trichlorbenzene is 108 C.- Not only are illmhaving gel points under '12. forming operations more expensive and trouble- Furfural can be mixed with chlorbenzene in some at high temperatures, but polyvinyl chloall proportions except very small ones to give soride is not perfectly heat-stable and has a tendlutions having gel points under 72.

ency to split oil hydrogen chloride at elevated By following the method 01 this invention, teti temperatures. rahydroturiural and furiuryl alcohol may be It is an object of this invention to provide a mixed in. widely varying proportions with chlomethod of lowering the gel points of solutions rinated benzene or its homologues to give soluoi gamma polyvinyl chloride in chlorinated bentions having lower gel points than those exhibited "zent and its homologues. by solutions made with either solvent alone. i

It is another object of this invention to pro- It is to be understood that this invention is vide improved solvents for gamma polyvinyl applicable to gamma polyvinyl chloride in a plaschloride. ticized or unplasticized state; and that the term Other objects will be apparent from the folgamma polyvinyl chloride is used in the claims lowing description of the invention. to include plasticired compositions. 1

I have discovered that solvents containing iur- Although I have herein disclosed specific emiuryl or tetrahydroiuriural groups tend, when bodiments of my invention, I do not intend to mixed with chlorinated solvents, to markedly delimit myself solely thereto, for it will be obvious press the 8 P ts 0! t e solut ons. This into those skilled in the art that many modificaw vention accordingly contemplates the incorporations thereof are within the spirit and scope of 4 tion of a member of the class consisting of the invention as deflnedinthe appended claims. iuriuryl alcohol, furfural, tetrahydroiuriuryl al- I claim: cohol, and tetrahydroiuriural in chlorbenzene, 1. The method of making a solution of gamma trichlorbenzene, chlortoluene. and other homopolyvinyl chloride which comprises dissolving lo es f h ed benzene. gamma polyvinyl chloride in amixed solvent con- 1 The invention may be better understood by taining a member of the class consisting of chloreierring to the accompanying drawing in which rinated benzene and its homologues and a mem- Flg. 1 representsthe gel points of 10% gamma ber o! the class consisting of turiuryl alcohol. polyvinyl chloride solutions in mixtures-oi tetiurfural, tetrahydroiurmryl alcohol, and tetrarahydroiuriuryl alcohol with both chlorbenzene hydroiurfural in such proportions that the gel and chlortoluene: and point is lower than the gel points obtained with Fig. 2 represents the gel points of similar soeither solvent alone.

lutions in mixtures of iurmral with both chlor- 2, A mu of gamma polyvinyl chloride in benzene and c r u ea mixed solvent containing a member of the class as The el po s were ed by dis olving 10 consisting oi chlorinated benzene and its homologues and a member of the class consisting of furfuryl alcohol, iurfural, tetrahydrofurturyl alcohol, and tetrahydrofurfural, in such proportions that the gel point is lower than the gel points obtained with either solvent alone.

3. A solution of gamma polyvinyl chloride in a mixed solvent containing furfural and a member of the class consisting of chlorinated 'benzene and its homologues, in such proportions that the gel point is lower than the gel points obtained with either solvent alone. 7

4. A solution of gamma polyvinyl chloride in a mixed solvent containing tetrahydroturfuryl alcohol and a member of the class consisting oi? chlorinated benzene and its homologues, in such proportions that the gel point is lower than the gel points obtained with either solvent alone. RALPH F. WOLF;

CERTIFICATE OF CORRECTION. Patent No. 5L 1 March 11, 19m.

RALPH F. WOLF.

It is hereby certified that error appears in the printed specification of the above r'lmnbared patent requiring correction-as follows: Page 1, first column, line 9-50, for "benzent" read --be nzene--; line 57, fdr "tetrahydrofurfural" read -tetra.hydrofurfuryl-; and that the said Letters Patent should be read vdththis correction therein that the same may conform to the record at the case in the Patent Office. Signed and sealed this 1st day of Septenber, A. D. 191:3.

Henry Van Arsdale (Seal) Acting Commissioner of Patents. 

